title: Designing materials for plasmonic systems: the alkali-noble intermetallics.
abstract: We use electronic structure calculations based upon density functional theory to search for ideal plasmonic materials among the alkali-noble intermetallics. Importantly, we use density functional perturbation theory to calculate the electron-phonon interaction and from there use a first order solution to the Boltzmann equation to estimate the phenomenological damping frequency in the Drude dielectric function. We discuss the necessary electronic features of a plasmonic material and investigate the optical properties of the alkali-noble intermetallics in terms of some generic plasmonic system quality factors. We conclude that at low negative permittivities, KAu, with a damping frequency of 0.0224 eV and a high optical gap to bare plasma frequency ratio, outperforms gold and to some extent silver as a plasmonic material. Unfortunately, a low plasma frequency (1.54 eV) reduces its utility in modern plasmonics applications. We also discuss, briefly, the effect of local fields on the optical properties of these materials.
authors.affiliation: Institute for Nanoscale Technology, Department of Physics and Advanced Materials, University of Technology, Sydney, 15 Broadway, NSW 2007, Australia.
authors.forename: M G
authors.initials: MG
authors.lastname: Blaber
authors.forename: M D
authors.initials: MD
authors.lastname: Arnold
authors.forename: M J
authors.initials: MJ
authors.lastname: Ford